I'm really interested in the concept of auras and how to apply them to a construct as features built into the creature.

In the case of this monster, called the Clockwork behemoth, I've
created something called a Bladestorm Aura.

The idea is that, once
activated, the behemoth has a "defense system" consisting of 8 blades
which revolve around the automaton at very high speeds, sort of like a
chain saw. Anyone caught in it takes damage.

This is what it looks like so far. Feedback is appreciated:

Bladestorm Aura (weapon) aura 1; The clock work behemoth has a defense
system consisting of eight jagged blades which revolve around the
creature at high speeds. Anyone caught in the bladestorm aura at the
start of their turn takes 10 weapon damage.